Haswell (formerly known as Rockwell) is the codename for a processor microarchitecture developed by Intel as the successor to the Ivy Bridge architecture. It uses the 22 nm process. Intel officially announced CPUs with this microarchitecture on June 4, 2013 at Computex Taipei 2013. With Haswell, Intel introduced a low-power processor designed for convertible or 'hybrid' Ultrabooks, having the Y suffix.